χ2 tests

Definition

χ2 tests, also known as chi-square tests, are statistical tests used to determine if there is a significant association between two categorical variables. It compares the observed frequencies in a sample to the expected frequencies under a null hypothesis.

Related terms

Two-way table: A two-way table is a table that displays data for two categorical variables. It shows how many observations fall into each combination of categories.

Test for Homogeneity: The test for homogeneity is a specific type of χ2 test that determines whether the distribution of one categorical variable differs across different levels of another categorical variable.

Expected frequencies: Expected frequencies are the values that would be expected in each category if there was no association between the variables being tested. They are calculated based on the assumption of independence between variables.